The
database resides in The Collaboratory for the Multi-scale Chemical
Science (CMCS) supported by the
U.S. Department of Energy's Office of Mathematical, Information, and
Computational Sciences.The
mission of CMCS is to bring together leaders in scientific research and
technological development across multiple DOE laboratories, other
government laboratories and academic institutions to develop an open
"knowledge grid" for multi-scale informatics-based chemistry research.
Our CMCS team name isPremixed
Turbulent Flames Working Group.
The team's page consists of

Folder
for each flame configuration where you can

browse for available data

add your own data
to the folders

Additional folders for

Discussion
on data analysis

Chat

Lookup monenclature and
common
definitions

Lists of publications and
links

The
Premixed Turbulent Flames Working Group site is in the beta-testing
stage and will open to accept members by summer 2006. Please check back
for updates

Overview
- Oblique flames are generated by placing a flame
holder
at the center of the burner. The turbulent flame brushes Interact
with
incident turbulence and grow thicker away from the stabilizer. In
most
laboratory experiments, the sizes of the flame holder were kept to a
minimum
so to reduce shear and its influences on the developing turbulent
flames. Oblique Flames are either
plane-symmetric
or
axi-symmetric.

Plane-Symmetric
Oblique FlameA V-flame stabilized by a small
rod is
the most common rendition of a plane-symmetric laboratory oblique
flame.
There are over 40 experimental publications using this configuation.Click here
to
access publication list and database for v-flames.

Axi-symmetric
Oblique FlameA small bluff body or pilot flame
placed
at the center of the burner generates an axi-symmetric oblique flame
that
shapes like an inverted cone.Click here
to access publication list and database inverted cone-flames.

Overview
- Envelope flames
are generated by anchoring the flames at the rim of the burner. The
turbulent
flame brushes burn towards the center and merge to form an envelope
over
the premixture. Under moderate flow and turbulence levels where open
flame
tip and local extinction (or quenching) are not likely to occur, the
premixture
cannot escape without burning. Because the burner rim is not a very
effective
flame stabilizer, most studies use pilot flames to extend the test
matrix.
Envelope flames can be plane-symmetric or
axi-symmetric
depending on the geometry of the burner.

Plane-Symmetric
Envelope FlameThese flames are generated by the
use
of a rectangular shaped burner (or slot burner) with flame brushes
originating
at two opposite edges. To preserve the "envelope" features, the two
remaining
sides of the burner need to be confined.Click here
to
access publication list and database for 2D envelope-flames.

Axi-symmetric
Envelope FlameThese flames are also known as
Bunsen
flames. Whereas conventional laboratory Bunsen flames are rich premixed
flames, laboratory Bunsen flames of interest to premixed turbulent
flame
studies are almost all less than stoichiometry. Click here
to access publication list and database for Bunsen-flames

Fundamental properties for
validating
theories and simulations:

mean flame height
(definition)

mean turbulent burning
velocity
(definition)

Burner features that affect flame
properties

pilot flames adding energy
to
the system

non-uniform velocity and
turbulence distributions
under high Re conditions

Overview
- Unattached
flames do not require a flame anchor. They are sustained in divergent
flows
by
vitrue of the propagating nature of premixed combustion. These flame
brushes
are locally normal to the approach flow and free to repond to incident
turbulence without being constrained or "pinned down" at the flame
attachment
point.

Unattached
flames in impinging flowsThe divergent flow generated by
impingment
on a stagnation plate or against each other allows the flame to
position
itself at a short distrance upstream of the stagnation plane. Click here
to
access publication lists and database for stagnation-flame.

Unattached
flames in swirl-generated diverging FlowSwirling flow with low swirl
number (typically less
than 0.6) produces a divergent flow with the swirling motion confined
to
the flow periphery. In the center region, the turbulent flame brush
experiences
no swirling motion. Click here
to access publication list and data base for low-swirl burner.

Overview
- The initial
velocity profile of a jet flame resembles that of a fully developed
pipe flow. The flame brush is mostly confined within the mixing layer
of the jet. The flames are very oblique to the incident flow and look
slender and tall.

Piloted
jet flame A pilot flame is usually
required
to stabilize a jet flame due to its high exit velocity. In the
example shown here, a relative large pilot flame (blue disk at the
flame base) is used so to produce a very lean jet flame.
Publication lists and database for
piloted jet flames under development

Overview
- When a large
bluff-body blocks a relative large area of the burner opening, the
flame is ahcnored by the hot products trapped inside the wake. The
properties of the wake (i.e. size and recirculation strength) have a
significant influence on flame properties.

Flame
Stabilized by a large bluff bodyThe wake
region of the bluff body is outlined by the tapering shape of the flame. The influence
of the wake diminishes downstream and the flame brush flares outward

Publication lists and
database for large bluff-body flames under development

Overview
- High swirl
promotes the formation of a recirculation zone and is the essential
mechanism
for flame stabilization. Swirling flows can be produced either by
tangential jet injections or by vane swirlers. The flame is ahcnored by
the hot products
trapped inside the recirculation zone. The swirl rate (usually
expressed in terms of a swirl number) dictates the sizes and stength of
the recirculation zone
and also most of flame properties.

High-swirl
flame generated by a vane swirlerThis swirler has a ceter
bluff body surrounded by 16 curved swirl vanes. For this particular design, the flame brush is
mostly outside of the wake region.

Publication lists and
database for large bluff-body flames under development